<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    body {
      margin: 0;
    }

    #wrap {
      margin: 20vh auto;
      width: 260px;
      height: 50vh;
      ;
      border: 1px solid #000;
      overflow: hidden;
    }

    #list {
      margin: 0;
      padding: 10px 5px;
      list-style: none;
      font: 16px/2 "宋体"
    }

    #list li {
      border-bottom: 1px solid #000;
    }
  </style>
</head>

<body>
  <div id="wrap">
    <ul id="list">

    </ul>
  </div>
  <script>
    {
      let list = document.querySelector('#list')
      list.innerHTML = [...('.'.repeat(100))].map((item, index) => `<li>这是第${index}个li</li>`).join("")
    }
  </script>
  <script>
    {
      let list = document.querySelector('#list')
      let startPoint = 0 // 按下时鼠标的位置
      let startEl = 0; // 按下时元素的位置
      let y = 0

      let move = e => {
        let nowPoint = e.clientY
        y = startEl + (nowPoint - startPoint)
        list.style.transform = `translate3d(0, ${y}px, 0)`
      }

      list.addEventListener('mousedown', (e) => {
        startPoint = e.clientY
        startEl = y
        document.addEventListener('mousemove', move)
        // 抬起之后
        document.addEventListener("mouseup", () => {
          document.removeEventListener('mousemove', move)
        }, {
          once: true
        })
      })


    }
  </script>

</body>

</html>